Oyster is used as a common name for a number of distinct groups of bivalve mollusks, which live in marine or brackish habitats. Oysters are an important food source in coastal areas, and oyster fisheries are an important commercial industry. See e.g., website en.wikipedia.org/wiki/Oyster.
The bivalve shells of live oysters are normally tightly closed. Individual oysters can be round or more commonly oval in shape (FIG. 1). One of the valves (half-shell) is generally more rounded or convex that the other half-shell. This rounded half-shell is commonly referred to as the cupped half-shell. The other half-shell, which is flatter, acts as a lid over the cupped half-shell. A single powerful oyster muscle—the adductor muscle, which is attached to the cupped half-shell, holds the two half-shells shut tightly. The two half-shells are also joined at a hinge joint located at the circumference of the shell by a hinge muscle.
FIG. 2, which is adapted from the website oysters.us/opening.html, shows topographic features or regions that are common to all oyster shapes. The beak portion is the pointed part of any oyster. The beak portion is shown pointing toward the bottom of the FIG. 2. The oyster's hinge joint muscle is found immediately above the beak. The lip or bill is the broad flat end vertically opposite the beak. The oyster's adductor muscle is generally found to the right of the median axis running from the beak to the bill, slightly above midpoint (i.e. in the upper right quadrant as shown in FIG. 2).
Oysters must be eaten alive, or cooked alive. Shucking, refers to process of removing of the oyster meat from the tightly-closed bivalve shell of an oyster. Shucking oysters is usually accomplished manually by hand. A mechanical tool, e.g., a shortbladed oyster knife, is inserted between the two halves of the bivalve shell, close to the hinge, and twisted to break the hinge and lever the oyster half-shells apart. The knife is then used to sever the adductor muscle at its point of attachment to the cupped half, and the oyster meat removed. If the meat is to be served on the half-shell, the detached meat is turned over, cleared of any shell fragments, and left in the cupped half-shell along with the natural liquor. See e.g., FIG. 3 and websites
marylandinfo.com/sponsorships/how_to_shuck_oysters.html
fao.org/wairdocs/tan/x5954e/x5954e01.htm.
The manual process of shucking oysters is labor intensive. Labor-reducing techniques that are deployed in the commercial food-processing industry for shucking oysters may include shearing off the hinge (e.g., by guillotine) and a wide range of treatments (e.g., chemicals, heat, cold, vacuum, microwave and laser treatments) that cause the shell to spring open. All these common commercial treatments that cause the oyster shell to self-open affect the freshness, integrity and quality of the oyster meat that is scraped out from the self-opened shell.
Attention is now directed to improved or different techniques for shucking oysters.
Throughout the figures, unless otherwise stated, the same reference numerals and characters are used to denote like features, elements, components, or portions of the illustrated embodiments.